Clinical applications of the Shack-Hartmann aberrometer

The efficacy of the Shack-Hartmann technique for measuring the optical aber rations of the eye was evaluated for four classes of clinical conditions as sociated with optically abnormal eyes. These categories (with specific exam ples) are: anomalies of the tear film (dry eye), corneal disease (keratocon us), corneal refractive surgery [laser-assisted in situ keratomileusis (LAS IK)], and lenticular cataract. We show that in each of these cases, it is p ossible to obtain at least a partial topographic map of the refractive aber rations of the patient's eyes, but severe losses of data integrity can occu r. We further show that the Shack-Hartmann aberrometer provides additional information about the eye's imperfections on a very fine spatial scale (< 0 .4 mm) which scatter light and further degrade the quality of the retinal i mage. Taken together, spatial maps of the variation of optical aberrations and scatter across the eye's entrance pupil represents an improved descript ion of the optical imperfections of the abnormal eye.